Project 6.2. Task-specific Project 2: Multiplexed in-vivo endoscopy by Raman imaging of cancertargeting nanoparticles Principal Investigator: Sam Gambhir Investigators: James Chan, Thomas Huser, Mike Mandella, Sebastian Wachsmann-Hogiu This task-specific project will use nanoparticles (Fig. 20) and intravital Raman imaging at near-infrared wavelengths to image molecular targets in the colon. This project supports aim 1 by providing an alternative set of imaging probes and new instrumentation that may permit multiparametric analysis of Gl cancer. A significant concern for those developing molecular imaging tools is that detection of a single molecular marker may be insufficient for specific detection and staging. Raman imaging of multiple particles with distinct spectra and molecular tags may address this concern. This possibility will be addressed through the following specific aims: Aim 1: To develop a compact colonoscope for in-vivo Raman imaging in patients Aim 2: To develop and characterize multiplexed Raman nanoparticles for Gl cancers Aim 3: To image early dysplastic lesions of the colon through in-vivo imaging of Raman nanoprobes.